Cloud computing is a term that is used to refer to accessing remote computing resources provided by someone other than the user, using a network. The computing resources provided can include hardware, software or a combination of both. Typically the user is charged for the services accessed using a pay-per-use model. The most common network used to access remote computing resources is the Internet. Cloud-based services can be accessed using a web browser or a light-weight desktop or mobile application. Cloud computing shares the resources of a single physical computer with more than one user. For example a server “in the cloud” may store the data for several or many customers on the same physical computer.
A cloud typically includes a number of physical computers that appear to a user to be a single computer. The computers of the cloud are typically virtualized (made into virtual machines) to maximize resource usage. A single virtualized computer can appear to a user to be a number of physical computers. A virtual machine shares the resources of a single physical computer among multiple different virtual computing environments.